Silencer



H. P. MAXIM SILENCER Sept. 28 ,71926. 1,601,1374

Filed Nov. 26. 1924 2 sheets-sheet 1v INVENTOR BY *'M A TORNEYS H. P.MAXIM Sept. 28 1926.

SILENCER Filed NOV. 26, 1924 2 Sheets-Sheet 2 INVENTOR ll u ll ATTORNEYSPatented Sept. 28, 1926..

N UNITED vSimfree PATENT OFFICE.

HIRAM PERCY MAXIM, OF HARTFORD, CONN ECTCUT, ASSIGNOR TO MAXIM SILENCERCOMPANY, OF HARTFORD.r CONNECTICUT, A CORPORATION OF CONNECTICUT.

SILENCER.

Application led November 26, 1924. Serial No. 752,440.

This invention relates to silencers such as are used for silencing theexplosive exhaust noises of internal combustion engines, intake of aircompressors and the like. y

i More particularly, it relates to that type of silencer wherein the.exhaust gases are constrained to pass from an `axial or central chamberthrough a spiral passageway or a series of spiral passageways and bedelivered from said passageway through a narrow an nular opening orslot, either to a succeeding spiral passageway or to the atmosphere atthe periphery of the device.

One object of the invention is to provide an improved and simplifiedsilencer of lthe above type and one which is capable of cooperating withsimilar or duplicate members whereby more or less silencing capacity maybe provided by the assembling together of a larger or smaller number ofthe same members.

Further objects of the invention are .to provide certain improvementstending to in; sure strength and rigidity of construction; to facilitatethe economical quantity production of silencers of large capacity; torender practical 'the construction of larger silencers in whichprovision is made for varying the capacity thereof; and to providevarious other improved features of constructionI contributing to theproduction of eiiicient and reliable silencers at low manufacturingcosts.

To the accomplishment of the above and further objects, as will.hereinafter appear, the invention consists'in' the features ofconstruction and in the combination and arrangement of parts which. willbe first describedvand particularly pointed out in the claims.

The invention will be explained in connection with the ,accompanyingdrawings, lin which2 Fig. 1 is a longitudinal sectional view of asilencer constructed in accordance with the present invention; v

Fig. 2 is a sectional view taken on the line 2-i-2 of Fig. 1;

Fig. 3 isa longitudinal half sectionalized 50 view of a modified form ofthe invention;

and Fig. 4 is a sectional view taken 4?-4 of Fig. 2, v l

on the line Referring to the drawings, and particularly to Figs. 1 and2, the improved silencer therein shown comprises two annular members 1and 2 which. are assembled side-byside, as shown in Fig. 1, and to whichan end plate 3 is secured.

The members 1 and 2 are preferably constructed of cast iron as integralcastings,

uous winding or spiral passageway 6 leadingfrom the center of the memberto a point adjacent the periphery thereof. To this end, each of theannular members 1 and 2 comprises flat annular plates with a centralaperture, and what is in effect a spiral rib 4 which projects at rightangles to the plate and which forms between its convolutions the windingor spiral passageways 6 for the exhaust gases. In practice, it ispreferred t-o malte the ribs 4 not as ltrue spirals but concentriccircular segments for somewhat more than lthree quarters of a circle andto connect the corresponding ends of each concentric portion with theopposed ends of the ribs of the next smaller diameter, as clearly shownin Fig. 2. The outer convolution lor concentric circular segment of therib 4 is spaced from the periphery of the annular plate a distance whichis slightly greater than the distance between the inner concentriccircular segments. There isalso formed on each annular plate a circularrib or flange 5. This flange 5 also projects at right angles to theplate, but it projects a `distance which is slightly` less than thedistance that the spiral rib 4 projects for a purpose which will behereinafter described. This flange 5 forms, in conjunction with theouter convolution of the spiral rib 4, an annular channel7 into whichthe spiral passageway 6 opens. The annular members 1 and 2 are alsoprovided with apertured ears and each one is formed to provide a contin-Y or bosses 8 for a purpose which will be readily apparent.

The members 1 and 2 are assembled side by side' in coaxial relation sothat the free end of the rib 4 on the member 1 engages the unribbed faceof the member 2, the latter closing the open sides of the winding passageway 6 between the rib 4 on the member 1. The end plate 3 is likewiseassembled adjacent the free end ofthe rib 4 on member 2, thereby closingthe open sides of the winding passageway 6 between the rib 4 on thismember. rlhe end plate 3 is solid throughout and also closes at one endthe axial chamber l2 formed by the central` apertures in the members 1and 2.

It will be seen, however, that neither the unribbed face of member 2 northe end plate 3 Vcompletely closes the annular channel 7 due to theshorterdistance that the rib 5 projects from the annular plates of themembers l and 2. Thus the open end of Ithis annular channel 7 in each ofthe members l and 2 is almost closed, forming annular chambers eachhaving a narrow annular port 9 extending around the outer periphery ofthe device. The end plate 3 is provided with apertures which registerwith the bosses 8v whereby the different parts of the device Yaresecurely fastened together by means of the tie bolts 10 extending fromthe bosses. The member l is also preferably provided with an internallythreaded axial boss l1, by means of which the silencer is adapted t'o beattached to the exhaust pipe of an engine.

In the present embodiment, the bosses or ears 8 extend the full width ofeach member whereby the annular opening 9 is interrupted at thesepoints. It is readily apparent, however, that these bosses may be formedso that there will be practically no interruption of the opening 9.

In use, the gases and sound waves pass into Athe axial chamber l2, thenthrough the spiral silencing passageways 6 and into the annular chambers7, and are dispersed into the atmosphere through the narrow annularopenings 9. rlhe sound waves passing from the axial chamber l2 arebroken up by re-` peated reiections in the winding passageways 4 and asa result the gases leaving the annular ports 9 of the silencer aresubstantially noiseless.

It will be obvious that the capacity of the silencer will be determinedby the number of the units, represented by the annular members l and 2employed. rlhus a manufacturer is enabled to readily construct asilencer of any desired capacity by simply assembling the requirednumber of the same units with an end plate and properly securing themtogether.

After a silencer of this type has been in use, its capacity can bereadily changed as may be desired by the removal of units from theseries, or the addition thereto of more units, it being only necessaryto employ bolts of the proper length to accommodate the number of unitsemployed.

It will be seen that the above described silencer is of extremely simpleconstruction and that all the parts thereof may be advantageously formedof metallic castings.

It' will also be apparent that a silencer of the above type may beconstructed of only one annular member and an end plate or that a seriesof three or more members Also, in this specific form the two l membersland 2 are assembled with the 9 Vand 9 with approximately the samecircumferential area. The member '2' is also peferably constructed witha non-apertured end wall for a reason which is readily apparent. Eachmember l and. 2 is also provided with the apertured ears 8 and tie bolts10 in order to firmly hold thecassembly together. i

It will thus be seen that a slightly modiiied form of silencer has beenconstructed wherein the action of the sound waves and gases is similarto the action in the form shown in Figs. l and 2. In this form, however,the sound waves are broken up more than in the previously described formdue tdthe repeated narrow annular discharge openings 9 and 9,which-successively allow buta small portion of the wave front to pass tothe succeeding spiral passageway and eventually to the atmosphere.

It will also be apparent that the members l and 2 may be assembled inthemanner shown in Figs. l and 2, that is, with their unribbed facesadjacent'the open side of the channels of the next preceding member. Insuch a case, each member is centrally apertured and an end plate isprovided.

The invention has been disclosed herein for illustrative purposes in itspreferred embodiment and also with the aid of certain modificationsthereof, but it is to be understood that the scope of the invention isdelined by the appended claims rather than by the foregoing description.

Claims:

l. A silencer comprising, a centrally chambered annular member having aspiral rib and a circular rib projecting from one side thereof toprovide an interconnecting spiral and circular channel, said circularrib projecting from said side a shorter distance than said spiral rib,and a closure for the open side of said channels abutting said spiralrib and slightly spaced from said circular rib,

llo

whereby a closed spiral passageway leading into an annular chamberhaving an annular outlet port is provided. i

2. A silencer comprising a series of centrally chambered annularmembers, each having a .spiral and a circular rib projecting from oneside thereof to provide an interconnecting spiral and circular channeltherein, said circular rib projecting from said-side a shorter distancethan said spiral rib, each succeeding member of said series adapted toform a closure for the open lside of the channels of the next precedingmember and to abut the spiral rib and be slightly spaced from thecircular rib thereof whereby a series of closed spiral passageways, eachhaving an annular outlet port, is provided.

3. A silencer comprising an annular member having an end wall with aspiral rib and a circular rib projecting from one side thereof toprovide an interconnecting spiral and circular channel, said circularrib projecting from said end wall a distance slightly lessA than saidspiral rib, whereby when the open side of said channels is closed aclosed spiral passageway having an annular discharge y opening isprovided.

4. A silencer comprising a series of annular members each having an endWallwith one or more alternate spiral and circular ribs projecting fromone side thereof to provide4 interconnecting spiral and circularchannels, said circular ribs projecting from said end wall a distanceslightly less than said spiral ribs, each succeeding member of saidseries adapted to form a closure for the open side of the precedingmember, whereby when the open side of said channels is closed a seriesof closed spiral passageways each y having an annular discharge openingis 'provided 5. A silencer comprising a series of centrally aperturedmembers, each having a spiral rib and circular rib projecting from oneside thereof to provide an interconnecting spiral and circular channel,said circular rib projecting'from said side a shorter distance than saidspiral rib, an end plate for the last member of said series, saidmembers'being assembled with the unribbed face of' each succeedingmember abutting the spiral rib of the next preceding member and slightlyspaced from the circular ribI thereof and with said end plate similarlypositioned against the ribbed face of the last member of said series toprovide a. central chamber closed at one end and having a series ofclosed spiral passageways leading therefrom to an annular chamber havingan annular exhaust opening, and means comprising tie bolts extendingthrough said members and end plate to hold same in assembled position. 4

ln testimony whereof I have affixed vmy signature. y

HIRAM PERCY MAXIM.

